8,325 research outputs found
Microrna let-7: an emerging next-generation cancer therapeutic
In recent years, various rna-based technologies have been under evaluation as potential next-generation cancer therapeutics. Micrornas (mirnas), known to regulate the cell cycle and development, are deregulated in various cancers. Thus, they might serve as good targets or candidates in an exploration of anticancer therapeutics. One attractive candidate for this purpose is let-7 (“lethal-7”)
Zirconia based nucleic acid sensor for Mycobacterium tuberculosis detection
Nanostructured zirconium oxide (ZrO2) film (particle size ∼ 35 nm), electrochemically deposited onto gold(Au) surface, has been used to immobilize 21-mer oligonucleotide probe (ssDNA) specific to Mycobacterium tuberculosis by utilizing affinity between oxygen atom of phosphoric group and zirconium to fabricate DNA biosensor. This DNA-ZrO2/Au bioelectrode, characterized using x-ray diffraction, Fourier transform infrared spectroscopy, cyclic voltammetry, and scanning electron microscopy techniques, can be used for early and rapid diagnosis of M. tuberculosis with detection limit of 0.065 ng/μL within 60s
The Mid-Infrared Spectrum of Star-Forming Galaxies: Global Properties of PAH Emission
We present a sample of low-resolution 5-38um Spitzer IRS spectra of the inner
few square kiloparsecs of 59 nearby galaxies spanning a large range of star
formation properties. A robust method for decomposing mid-infrared galaxy
spectra is described, and used to explore the behavior of PAH emission and the
prevalence of silicate dust extinction. Evidence for silicate extinction is
found in ~1/8 of the sample, at strengths which indicate most normal galaxies
undergo A_V < ~3 magnitudes averaged over their centers. The contribution of
PAH emission to the total infrared power is found to peak near 10% and extend
up to ~20%, and is suppressed at metallicities Z < ~Z_sun/4, as well as in
low-luminosity AGN environments. Strong inter-band PAH feature strength
variations (2-5x) are observed, with the presence of a weak AGN and, to a
lesser degree, increasing metallicity shifting power to the longer wavelength
bands. A peculiar PAH emission spectrum with markedly diminished 5-8um features
arises among the sample solely in systems with relatively hard radiation fields
harboring low-luminosity AGN. The AGN may modify the emitting grain
distribution and provide the direct excitation source of the unusual PAH
emission, which cautions against using absolute PAH strength to estimate star
formation rates in systems harboring active nuclei. Alternatively, the low star
formation intensity often associated with weak AGN may affect the spectrum. The
effect of variations in the mid-infrared spectrum on broadband infrared surveys
is modeled, and points to more than a factor of two uncertainty in results
which assume a fixed PAH emission spectrum, for redshifts z=0-2.5.Comment: Accepted for publication in ApJ, 24 pages (abstract typo fixed,
reference added
Carbon nanotubes — chitosan nanobiocomposite for immunosensor
Carboxylic group functionalized single walled (SW) and multi walled (MW) carbon nanotubes (CNT) have
been incorporated into biopolymer matrix of chitosan (CH) to fabricate nanobiocomposite film onto indium–
tin–oxide (ITO) coated glass plate for co-immobilization of rabbit-immunoglobulin (r-IgGs) and bovine
serum albumin (BSA) to detect ochratoxin-A (OTA). The results of electrochemical studies reveal that
presence of both CNT results in increased electro-active surface area of CH leading to enhanced electron
transport in these nanobiocomposites. Moreover, in CH–SWCNT and CH–MWCNT nanobiocomposites the
availability of NH2/OH group in CH and surface charged CNT also increases loading of the r-IgGs resulting in
enhanced electron transport responsible for improved sensing characteristics. Compared to BSA/r-IgGs/CH–
MWCNT/ITO immunoelectrode, electrochemical response studies of BSA/r-IgGs/CH–SWCNT/ITO immunoelectrode
carried out as a function of OTA concentration exhibits improved linearity as 0.25–6 ng/dL, detection
limit as 0.25 ng/dL, response time as 25 s, and sensitivity as 21 μA ng dL−1cm−2 with the regression
coefficient as 0.998
White Matter Changes Associated with Antipsychotic Treatment in First-Episode Psychosis
Second-generation antipsychotics are utilized extensively in the treatment of psychotic disorders and other psychiatric conditions, but the effects of these medications on human brain white matter are not well understood. We thus investigated the effects of second-generation antipsychotics on white matter integrity using tract-based spatial statistics in patients experiencing a first episode of psychosis with little or no prior antipsychotic exposure, and how potential changes were associated with metabolic side effects. Thirty-five (26 men/9 women) patients experiencing a first episode of psychosis received diffusion tensor imaging (DTI) exams, clinical assessments, and provided fasting blood samples at the onset of antipsychotic treatment, and then again after 12 weeks of treatment with either risperidone or aripiprazole in a double-blind randomized clinical trial. In addition, 35 (26 men/9 women) healthy volunteers received DTI exams at a baseline time point and then after 12 weeks. Patients demonstrated significant (
A self assembled monolayer based microfluidic sensor for urea detection
Urease (Urs) and glutamate dehydrogenase (GLDH) have been covalently co-immobilized onto a self-assembled monolayer (SAM) comprising of 10-carboxy-1-decanthiol (CDT) via EDC–NHS chemistry deposited onto one of the two patterned gold (Au) electrodes for estimation of urea using poly(dimethylsiloxane) based microfluidic channels (2 cm × 200 μm × 200 μm). The CDT/Au and Urs-GLDH/CDT/Au electrodes have been characterized using Fourier transform infrared (FTIR) spectroscopy, contact angle (CA), atomic force microscopy (AFM) and electrochemical cyclic voltammetry (CV) techniques. The electrochemical response measurement of a Urs-GLDH/CDT/Au bioelectrode obtained as a function of urea concentration using CV yield linearity as 10 to 100 mg dl−1, detection limit as 9 mg dl−1 and high sensitivity as 7.5 μA mM−1 cm−2
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